The refractive indices of diluted magnetic semiconductorCd1−xMnxTefilms on sapphire substrates have been determined bym-linespectroscopy to precision 0.001 at the wavelengths &lgr;=670, 785, and 1150 nm. Using these data, we designed double-layerCd1−xMnxTestructures on a GaAs substrate, achieving the integration of the magneto-optical waveguide on a semiconductor substrate. Good optical confinement of the waveguide mode was confirmed. ©1997 American Institute of Physics.